element

Material

Fermi Potential [neV]

Ctitical Velocity [m/s]

Loss Coefficient 10^-5

Ni

221 *

6.9 *

12.5 *

58 Ni

299 *

8.14 #

8.6 +

Be

252 *

6.9 *

0.5 +/2.8

Fe

-

6.3 #

8.5 +

Stainless Steel

187 *

6.0 *

-

Al

54 *+

3.2 *#

2.3 *+/4#

O2

70 *

3.7 *

0.6*

Teflon (PTFE)

123 *+

4.9 *

-

Fomblin

106.5 *

4.5 *

2.0 *

SiO2

135 *

5.1

-

Cu

168 +

5.66 #

15.5 +

Graphite

-

6.11 #

-

Polyethylene

-8.7 *+

-

-

Ti

-48 *+

-

-

Properties of Some Materials Typically Used with UCN
* F. Schorr, Thesis, TUM 1993
# V. Ignatovich, The Physics of Ultracold Neutrons, Larendon Press Oxford 1990, ISBN 0-19-851015-2
+ R. Golub, D. Richardson, S. Lamoreaux: Ultracold Neutrons, IOP Publishing Ltd, Philadelphia 1991, ISBN 0-7503-0115-5

Material	Fermi Potential [neV]	Ctitical Velocity [m/s]	Loss Coefficient 10^-5
Ni	221 *	6.9 *	12.5 *
58 Ni	299 *	8.14 #	8.6 +
Be	252 *	6.9 *	0.5 +/2.8
Fe	-	6.3 #	8.5 +
Stainless Steel	187 *	6.0 *	-
Al	54 *+	3.2 *#	2.3 *+/4#
O2	70 *	3.7 *	0.6*
Teflon (PTFE)	123 *+	4.9 *	-
Fomblin	106.5 *	4.5 *	2.0 *
SiO2	135 *	5.1	-
Cu	168 +	5.66 #	15.5 +
Graphite	-	6.11 #	-
Polyethylene	-8.7 *+	-	-
Ti	-48 *+	-	-